The beta-human chorionic gonadotropin (β-hCG)-positive rate, clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) per ET cycle were compared. Results: The β-hCG-positive rate , CPR , and LBR per ET cycle  were higher in the PRP group than in the control group, and the three variables  in the PRP group transferred with the blastocyst-stage embryos were also higher than those in the control group. The MR was similar in all groups. Conclusions: The LP-PRP treatment could improve the β-hCG-positive rate, CPR, and LBR in RIF patients undergoing FET cycles.Background: The clinical application of autologous leukocyte-poor platelet-rich plasma (LP-PRP) in patients with recurrent implantation failure (RIF) is rare. This retrospective observational cohort study aimed to evaluate the efficacy of LP-PRP intrauterine infusion in patients with RIF. Methods: Patients with RIF undergoing frozen embryo transfer (FET) from January 2019 to December 2021 ( Recurrent implantation failure (RIF) is a common issue, with an incidence of 10%, among patients undergoing assisted reproductive technology, despite developments in fertility treatment protocols . AlthougAutologous platelet-rich plasma (PRP), including platelets (PLT), growth factors, cytokines, a certain amount of white blood cells (WBCs), and red blood cells (RBCs) depending on the preparation method, is derived from fresh peripheral blood with a platelet concentration above the baseline . PRP is Two PRP separation systems are usually used. Buffy coat-based systems produce PRP with a high concentration of leukocytes, defined as leukocyte-rich PRP (LR-PRP). In contrast, plasma-based systems with a low concentration of leukocytes are designed to separate only the platelet and plasma portions from whole blood, defined as leukocyte-poor PRP (LP-PRP) . Previou2 or <18.5 kg/m2; (4) vitamin D deficiency; (5) uncontrolled endocrine, hematologic, or immunologic dysfunction; (6) endometrium thickness <8 mm; (7) severe male factor infertility; (8) thrombophilia and anticoagulant administration; (9) undergoing preimplantation genetic testing cycles or couples possessing genetic and chromosomal abnormalities. Finally, the patients receiving PRP treatment who provided a written informed consent were included in the PRP group (n = 64), and non-PRP patients were included in the control group (n = 54) according to patients’ personal willingness. All subjects gave their informed consent for inclusion before they participated in the study. This study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of The First Affiliated Hospital of Chongqing Medical University .A total of 118 patients with a history of RIF who underwent frozen embryo transfer (FET) at the Reproductive Medicine Center, The First Affiliated Hospital of Chongqing Medical University, China, from January 2019 to December 2021 were retrospectively analyzed. The inclusion criteria were (1) failure of clinical pregnancy after ≥3 ET cycles with at least 4 good-quality cleavage-/blastocyst-stage embryos; (2) women with RIF aged <40 years undergoing FET; (3) endometrium thickness ≥8 mm; (4) tubal factor infertility. The exclusion criteria were (1) availability of only poor-quality embryos; (2) congenital uterine abnormalities, untreated hydrosalpinges, endometriosis, adenomyosis, myoma, endometritis; (3) body mass index >30 kg/mAll patients were treated using the antagonist protocol for controlled ovarian stimulation according to our routine hospital protocol. Basal hormonal, ultrasonography (USG), karyotype evaluations, and ovarian reserve and acquired thrombophilia testing were performed. If there was any suspected problem of the uterine cavity and endometrium detected by two-dimensional USG, three-dimensional USG and confirmatory hysteroscopy were performed. The male partners were also evaluated and treated if necessary.Basic patient information, basal hormonal evaluation results, serum beta hCG (β-hCG)-positive rate per ET cycle, clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) were determined. The primary outcome measures were CPR and LBR, defined as ultrasonographic confirmation of a live intrauterine pregnancy and after at least 24 weeks of pregnancy per transfer cycle, respectively. The secondary outcomes were β-hCG-positive rate per ET cycle and MR, defined as a serum β-hCG level > 5 mIU/mL and termination of pregnancy with an ultrasound confirmation before 20 weeks, respectively.First, we selected the appropriate peripheral vein for puncture. PRP was prepared using the NIGALE Blood Composition Separator (NGLXCF-3000), manufactured by NIGALE Sichuan Biomedical Co., Ltd. in Chengdu City, Sichuan Province, China. In brief, self-inspection was completed after the startup process, the PLT separation program was selected, and the parameters were set. The consumables were installed according to the instructions, and the sodium citrate anticoagulant was added automatically by a machine at an anticoagulant/blood proportion of 1:11. After initiating the blood collection preparation, venipuncture was performed with a 16G needle after disinfection. The “blood collection” button was pressed to run the machine automatically. Whole blood (1 mL) was left aside to obtain the PLT and white blood cell (WBC) count. Then, about 300 mL of whole blood was drawn into a machine for centrifugation, and the PLT was resuspended with plasma to obtain the autologous PRP (approximately 20 mL). Finally, the remaining RBC and plasma left in the machine were automatically transfused back into the patient. The whole collection process was finished after one cycle of separation.The collected PRP was divided into eight bags (approximately 2.5 mL/bag) using sterile tubing welders  and a heat machine . The fresh PRP from one bag was infused immediately, and the remaining seven bags  were kept in a refrigerator  at –80 °C . For patThe endometrium was prepared by a hormone replacement treatment protocol. After ovarian quiescence was confirmed by vaginal ultrasound, the endometrial preparation for ET was performed on days 2–3 of menstruation with increasing estradiol valerate  or femoston  administration . After 12–16 days on estrogens, the endometrial thickness (EMT) and triple-layer pattern were measured using vaginal ultrasound. When EMT ≥ 8 mm was achieved, progesterone supplementation was initiated vaginally  and oral dydrogesterone administration . Estradiol (E2) and progesterone (P) were determined to ensure that no spontaneous ovulation had occurred. The method of progesterone supplementation was based on the hospital protocol for luteal phase support.On the day before ET, endometrial thickness was determined using vaginal ultrasound, and the estradiol (E2) and progesterone (P) concentrations were measured. If serum P ≥ 10 ng/mL and E2 ≥ 100 pg/mL, ET was scheduled. The ET was performed on day 4 of P supplementation for day 3 cleavage-stage embryos and on day 6 of P supplementation for blastocyst-stage embryos. Then, 2 good-quality cleavage-stage embryos with at least 1 grade I embryo determined according to the Istanbul consensus  or 1–2 gApproximately 1 mL of autologous LP-PRP in the syringe connected to the ET catheter was infused into the uterine cavity using vaginal ultrasound guidance every time. After autologous PRP intrauterine infusion, the patient was left in bed for 10–15 min. Adverse events  were observed within 4 h of PRP intrauterine infusion. Two autologous LP-PRP intrauterine infusions per FET cycle were performed. One bag of fresh LP-PRP could be used to perform intrauterine infusion directly on day 1 of P supplementation. The other bag of frozen LP-PRP was activated by sudden heat shock in the Department of Blood Transfusion before intrauterine infusion: frozen LP-PRP stored at −80 °C was immersed in liquid nitrogen for 5 min and quickly warmed at 37 °C for 5 min, twice ,26. The t-test was used to compare the differences in patient characteristics. Multiple comparison analysis was performed using post hoc ANOVA. Non-normal-distribution variables are presented as medians , and the differences between groups were tested using the Mann–Whitney U test. The categorical variables are presented as frequencies (percentages) and were compared using the chi-square test. Logistic regression analysis was performed to evaluate the effect of the variables on CPR. Statistical significance was set at p < 0.05.Statistical analysis was performed using SPSS version 22.0 . The continuous variables are presented as means ± standard deviations for normally distributed data, and Student’s p = 0.009) were significantly higher in the PRP group than in the control group (p < 0.05), respectively. Although the MR appeared to be lower in the PRP group than in the control group, the difference between the two groups was not significant . No serious adverse events  were found in the PRP group, as shown in The pregnancy outcome variables between the PRP and the control groups are listed in n = 40) experienced better outcomes than those in the control group (n = 34). The β-hCG-positive rate , CPR per ET cycle , and LBR per ET cycle  in these patients were higher in the PRP group than in the control group. The MR was similar in the two groups (p > 0.05) (p = 0.03). A statistically significant number of patients with PRP treatment had higher odds of pregnancy than those in the control group.Patients with blastocyst-stage ET in the PRP group ( > 0.05) . Furthern = 24), the proportion of top-quality embryos was not significantly different from that in the control group (p = 0.09). Although the PRP group showed higher β-hCG-positive rate , CPR per ET cycle , and LBR per ET cycle , no significant differences were observed between the two groups. Moreover, the MR was also similar in the two groups (p = 0.498) (For those patients who had cleavage-stage ET in the PRP group (= 0.498) . In addi± 189.59 × 109/L and 553.33 ± 228.98 × 106/L), clinical pregnancy (the concentrations of PLT and WBC were 758.44 ± 428.81 × 109/L and 550.74 ± 286.36 × 106/L), and non-pregnancy groups (the concentrations of PLT and WBC were 652.67 ± 140.31 × 109/L and 496.33 ± 179.42 × 106/L) who accepted PRP intrauterine infusion. No significant between-group differences were identified in the PLT count at baseline, PLT count in PRP, PEC, and WBC count in PRP, indicating that the PRP preparation was standardized in all groups.p = 0.018 and p = 0.011). However, the multivariate regression analysis showed that only the PRP treatment  had independent effects on the outcome of CPR  and progesterone (P) levels, duration of infertility, number of previous ET attempts, and endometrial thickness and the CPR outcome during the FET cycle are presented in e of CPR . Moreoveβ-hCG-positive rate, CPR, and LBR during FET cycles in women with RIF, which is in agreement with other research [β-hCG 14 days after embryo transfer and showed no advantages in improving the miscarriage rate, which is consistent with our results [RIF is a challenging problem in the field of assisted reproductive technology. Recently, abnormal endometrial receptivity is considered a risk factor for embryo implantation failures . The resresearch . This is results .β-hCG-positive rate, CPR, and LBR were only found between the BSE, PRP, and BSE control groups, which is similar to observations in other studies [n = 16, control n = 8) and two-embryo  transfer groups. Although the sample size was too small, the advantages of the PRP treatment displayed a notable positive trend. Moreover, there is the possibility that some of the PRP was flushed out after intrauterine infusion, and the actual quantity retained in the cavity could be less than that administered. However, the injection of PRP into the sub-endometrium did not provide any more advantages than PRP intrauterine infusion [According to the results of the blastocyst-stage embryos (BSE)/cleavage-stage embryos (CSEs) transfer, further analysis of the data revealed that statistical differences in the  studies ,30, wher studies . In factinfusion . Therefo6/L) in our PRP sample, defined as LP-PRP, was lower than that in LR-PRP (7991 × 106/L) [To our knowledge, research on the efficacy of PRP intrauterine infusion for patients with RIF is ongoing. Positive results have been reported in several studies ,30,31. H× 106/L) . LP-PRP In this study, some advantages of PRP preparation using an automatic Blood Composition Separator were noted compared to the manual preparation mentioned in the literature. First, according to the equipment operation protocol, the entire process was conducted in a completely closed state, which could avoid potential contamination caused by the manual preparation. No infections were found in the PRP group. Second, the simple process only required 15–20 min, which was less than the time required by the manual methods (~45 min) . In thisAs we know, the debate on the criteria for PRP intrauterine infusion schedule for a patient with RIF is ongoing. The time of PRP infusion differs between studies . TherefoSince progesterone limits the possibility of real endometrial growth, the potential biological effect of PRP infusion could be explained by proinflammatory, chemotactic, angiogenic, and antiapoptotic effects . Among tβ-hCG-positive rate, CPR, and LBR during FET cycles in patients with RIF rather than common LR-PRP. Second, both the fresh PRP and the activated frozen PRP were utilized per FET cycle, which is different from the majority of protocols. Finally, the PRP preparation technique and storage condition in this study were standardized [The strength of our study is that we utilized LP-PRP intrauterine infusion prepared by a machine for the first time to improve the dardized .However, there are certain limitations in this study. First, the efficacy of LP-PRP and LR-PRP was not compared simultaneously in this study because no LR-PRP preparation is carried out in our center, despite a series of reports revealing the efficacy of LR-PRP in RIF. Second, this is a review of data from a single center, which might have led to inherent biases and requires further external validation. Prospective randomized controlled studies with large cohorts in the LR-PRP and LP-PRP groups are required due to the limited sample size and lack of LR-PRP preparation. Finally, the heterogeneity of the preparations and the mechanism of LP-PRP in improving CPR and LBR are unclear, so further research is necessary to clarify these issues.β-hCG-positive rate, CPR, and LBR during FET cycles in women with RIF. However, the data of our study did not reveal any advantage of the PRP treatment for MR. While the data in this study indicated that the LP-PRP treatment has the potential to improve the live birth rate for women with a history of RIF, a prospective large randomized controlled trial is required to generate high-quality evidence on its clinical use in patients with RIF.The LP-PRP treatment can improve the


After 30 days of indoor storage, the filtration efficiency of CM–2 remained above 94%. The self-curling melt-blown filtration material developed here could potentially be applied in the field of protective masks.Particulate matter (PM) and airborne viruses pose significant threats to both the environment and public health. As the most viable solution to prevent the inhalation of these pollutants, there is an urgent demand for face masks with excellent filtration efficiency and low-pressure drop. In this study, a crimped masterbatch (CM) is added to polypropylene feedstocks to produce curling fibers through melt-blown spinning. These curled fibers exhibit low filtration resistance and effective dust-holding performances when used for air filtration. The effect of adding CM on fiber diameter, pore size, crimp, porosity, roughness, and surface potential was studied. The filtration performance of the materials, including the PM filtration capabilities, recirculation filtration, and loading test performance, were also investigated. The results demonstrate that the degree of fiber crimp can be adjusted by incorporating varying amounts of CM. This curling was caused by the uneven shrinkage that occurred due to variations in thermal contraction between these polymers. The curled fibers created a fluffy structure in the fiber network and modified the distribution of pore sizes within it. Under the same filtration conditions as sodium chloride aerogel, CM–2 (PP:CM 8:2) exhibited similar filtration efficiency (95.54% vs. 94.74%), lower filtration resistance (88.68 Pa vs. 108.88 Pa), higher quality factor (0.035 Pa With the rapid development of global industry, airborne pollutants such as particulate matter (PM) and viruses pose huge risks to human health . The WHO−1 to 0.0309 Pa−1, representing a 12.8% improvement after optimizing the electrospinning parameters. The filtration efficiency and pressure drops were 93.6% and 89.0 Pa, respectively [Melt-blown nonwovens possess excellent filtration properties due to their high specific surface area, fine fiber diameter, and narrow pore size distribution ,13,14. Hectively . AlthougHerein, we propose a one-step strategy to fabricate self-curling melt-blown fibers by adding a crimped masterbatch to polypropylene feedstocks. When combined with the electrostatic electret effect, melt-blown filters exhibit high porosity and surface potential, making them efficient and low-resistance filters. The effects of adding CM on fiber diameter, pore size, porosity, roughness, and surface potential on filtration performance were investigated. The filtration performance of the materials, including the PM filtration capabilities, recirculation filtration, and loading test performance, was also studied. The preparation of self-curling melt-blown fibers represents a novel approach to creating high-efficiency and low-resistance air filters.3 density) with a melt flow rate (MFR) of 1800 g/10 min at 230 °C were purchased from China-Base Petrochemical Co., Ltd.  Crimped masterbatch , referred to as CM, were supplied by Keimei Plastifizierung Technik (Yantai) Co., Ltd. .Polypropylene (PP) pellets . Melt-blowing process parameters are listed in The samples with CM–0, CM–1, CM–2, and CM–3 were treated with corona electret. Corona charging utilizes a high-voltage electric field to trigger air breakdown, resulting in a charge being deposited on the polymer surface or captured by its traps. This experiment utilized a double-sided corona charging device, which comprises a high-voltage power supply and two sets of electrode wires. The sample was positioned between the electrode wire and the substrate. After applying a high voltage, charges are deposited on both sides of the melt-blown material, resulting in a double-sided electret effect. The applied voltage and charging time were 60 kV and 10–30 s, respectively.The surface elements of feedstocks were analyzed by energy-dispersive X-ray spectrometer . The Fourier transform infrared (FTIR) spectra of feedstocks were characterized via a Fourier transform infrared spectrometer . The thermal stability information of the melt-blown nonwovens was obtained through a thermogravimetric analyzer . The thermal behavior was studied via differential scanning calorimetry  in a nitrogen atmosphere. X-ray diffraction instrument  was used to characterize the crystallization of PP/CM blends. The test conditions were a wide-angle diffract-Cu target (5–90°) with a scanning rate of 2°/min. The melt flow index (MFR) of PP/CM blends was tested on a melt flow rate meter . The surface morphology of melt-blown nonwovens was investigated by scanning electron microscope (SEM)  after sputter-coating the samples with gold. The fiber’s diameter and distribution were analyzed from more than 100 random fibers by the software Nano Measurer 1.2. The pore diameter of the melt-blown nonwovens was characterized by a capillary pore diameter analyzer . To observe the effect of fiber curl shape on the roughness of melt-blown fiber nonwovens, the surface roughness of melt-blown fiber nonwovens was measured by white light interference optical profilometer . The surface potential of PP/CM nonwovens was tested on a non-contact electrostatic field meter .s is the surface density of the sample, t is the sample thickness, ρ is the density of the sample, ppρ is the density of PP, Wpp is the proportion of PP mass, CMρ is the density of CM, WCM is the proportion of CM mass.The thickness of melt-blown nonwovens was measured by a digital display thickness gauge , and the average thickness was obtained by taking 20 different points on the sample. The porosity P of melt-blown nonwovens is calculated according to Equations (1) and (2).2 at a flow rate of 85 L/min. The filtration efficiency was calculated by measuring the concentration of aerosol particles upstream and downstream of melt-blown nonwovens. The filtration efficiency (η) is calculated by the following equation:up and Cdown represent the concentration of aerosol particles in the upstream and downstream of melt-blown nonwovens, respectively.The filtration performance and pressure drop of melt-blown nonwovens were measured by a particle filtration efficiency tester  according to GB 2626-2019. The sodium chloride (NaCl) aerosol solution concentration was 2.0 wt%, and the particle diameter was normally distributed with a median diameter of 0.075 um and a geometric standard deviation of less than 1.86. Aerosol particles passed through the testing area of 100 cm1 is the pressure before filtration and P2 is the pressure after filtration.The pressure drop is calculated by measuring the gas pressure difference between the upstream air inflow side and the downstream air outflow side of the filter material. The pressure drop (∆P) is calculated by the following formula:fQ) is calculated by the following formula:Since filtration efficiency and pressure drop are conflicting, neither of them is valid for assessing the filtration performance of melt-blown nonwovens alone, so the quality factor is used to comprehensively assess the filtration performance of the material. The larger the quality factor, the better the filtration performance of the material. The quality factor  for N95. The dust holding capacity of melt-blown nonwovens was also evaluated by DR251XL, which is defined as the mass of particles deposited on the filter per unit area when the initial pressure drop doubles. The NaCl aerosol solution concentration was adjusted to 5.0 wt% and the air flow rate remained at 85 L/min. The dust holding capacity is calculated by the following equation:−1 and 2865 cm−1 were the stretching vibration carbon-hydrogen bond in –CH3. The signals at 2916 cm−1 and 2836 cm−1 were the stretching vibrations carbon-hydrogen bond in –CH2–. The bending vibration signals of –CH2– and –CH3 were 1457 cm−1 and 1375 cm−1, respectively [−1 from continuous methylene (n > 4) [The content and distribution of C, O, and N elements in PP and CM were explored by an energy spectrum instrument, as shown in ectively ,23,24. T (n > 4) , which wThermogravimetric analysis was conducted on CM plastics and PP/CM melt-blown fibers to evaluate their thermal stability. The results are presented in As depicted in The melt flow rate (MFR) of PP/CM polymer is shown in The melt-blown technology was utilized to prepare a filter that exhibited high filtration efficiency and ultra-low pressure drop. The aim was to investigate the impact of new curly melt-blown fibers on the filtration performance of particulate contaminants. The experiments were designed to optimize fiber structure based on the following criteria: (1) The fiber diameter and aperture should be small to enhance filtration efficiency. (2) The fiber should have a certain crimp and maintain high porosity to minimize filtration resistance. (3) The filter material should have a certain degree of looseness to increase dust capacity and improve service life. PP/CM melt-blown nonwovens with varying morphologies and structures were produced using low-viscosity polypropylene and high-viscosity coiled masterbatch.The melt-blown spinning performance of PP with varying levels of CM content was studied. The surface microscopic morphology was recorded by SEM, as presented in Fiber crimping is primarily attributed to differences in compatibility and viscosity between PP and CM. Polypropylene (PP) and polyethylene (PE) are likely to be the primary components of materials used for fiber curling. Both polypropylene (PP) and polyethylene (PE) are straight-chain hydrocarbon polymers. These materials are non-polar and crystalline, and they have a similar chemical structure, which makes them compatible with each other. During the melt-blowing process, low-viscosity PP and high-viscosity crimped materials generate longitudinal stress in the fiber section. This stress causes the fiber to deviate from its axial torsion, potentially resulting in a three-dimensional crimp structure . AlthougRoughness measurements were made on a randomly selected x-axis or y-axis in a certain area of melt-blown nonwoven. The fiber surface roughness of melt-blown nonwovens was characterized by measuring the mean square roughness (Rq) of the samples. The test results are shown in The pore size and size distribution of PP/CM melt-blown nonwovens were statistically analyzed, and the results are illustrated in To investigate the impact of the curling masterbatch on the electrostatic characteristics of PP/CM melt-blown nonwovens, the surface potential of the samples was measured. As depicted in During the process of charge decay, the surface charge of the nonwovens decreased rapidly in the first 144 h and then gradually slowed down and stabilized thereafter. The attenuation of surface potential is significantly higher for CM–2 (6.99 kV to 2.96 kV) and CM–3 (6.87 kV to 2.20 kV) compared to CM–0 (5.43 kV to 2.19 kV). This is because the melt-blown webs absorb a large amount of charge on the fiber surface after electret. The moisture in the air neutralizes the charge on the surface, leading to a rapid decay of the surface charge until it reaches a stable state . CM–2 an0.3 was extensively investigated at a flow rate of 85 L/min. Filtration efficiency, pressure drop, and quality factor (QF) were used as evaluation parameters [Melt-blown nonwovens exhibit high filtration efficiency, which enables them to effectively capture airborne particulate matter (PM). However, they also have high-pressure drop values, which means they can cause significant respiratory resistance. The balance between filtration efficiency and pressure drop is crucial when studying filtration materials. As shown in rameters . The filrameters ,45. From0.3. Compared to other samples, CM–2 has a high QF (0.035 Pa−1) and shows potential for use in air filtration.During the filtration process, the pressure drop generated by the airflow through the melt-blown nonwoven is solely influenced by its pore structure. The corona electret treatment has less effect on the structure of nonwovens. As depicted in the histogram in 0.3, PM0.5, PM1.0, PM2.5, PM5.0 and PM10.0 were conducted. As shown in 0.3 remained consistent at 94% even after 30 days (0.3) was tested at a flow rate of 32 L/min, as shown in To evaluate the efficacy of PP/CM melt-blown nonwovens under real atmospheric conditions, the filtration performance for PM 30 days f. The fi2 and 10.39 g/m2, respectively. The basis weight of both is approximately 30 g/m2, while the dust capacity of CM–2 reaches a relatively high level. This is because CM–0 primarily intercepts particles on the surface to form a dense filter cake structure, while CM–2 can rely on its porous structure to capture a significant number of particles internally [ternally . In addiThe initial filtration phase of melt-blown nonwovens is called the steady-state phase when the five effects of particle capture by the mesh include physical interception, Brownian diffusion, inertial deposition, gravitational sedimentation, and electrostatic adsorption ,48,49,50−1 vs. 0.028 Pa−1) and better dust holding capacity (10.39 g/m2 vs. 9.20 g/m2) compared to CM–0. After 30 days of indoor storage, the filtration efficiency of CM–2 remains above 94%. It is generally more desirable for consumers and mask manufacturers to maintain high filtration efficiency and minimize pressure drop. It’s believed that the self-curling melt-blown fibers developed in this work would be applied in the field of comfortable protective masks.In summary, self-curling melt-blown nonwovens with high filtration efficiency and ultralow pressure drop were successfully fabricated based on PP and CM. When CM is embedded in the polypropylene polymer, the fibers curl after the melt-spun fibers cool down. This curling was caused by the uneven shrinkage that occurs due to variations in thermal contraction between the polymers. The curled fibers create a fluffy structure in the fiber network and modify the distribution of pore sizes within it. The difference between these two polymers creates a “torsion effect” on the fiber cross-section, resulting in the formation of three-dimensional crimped fibers. An increasing CM content leads to an extension of the fiber’s curl and fluffiness but with a coarsening of the fiber size. Under the same filtration conditions of sodium chloride aerogel, CM–2 exhibited similar filtration efficiency (95.54% vs. 94.74%), lower filtration resistance (88.68 Pa vs. 108.88 Pa), higher quality factor (0.035 Pa


Psychological distress is highly noticeable among caregivers working in residential youth care (RYC). Maintaining and enhancing caregivers’ professional mental health and quality of life is crucial to achieve effective outcomes in RYC. Nevertheless, trainings to protect caregivers’ mental health are scarce. Considering the buffering effect over negative psychological outcomes, compassion training could be beneficial in RYC.This study is part of a Cluster Randomized Trial examining the effects of the Compassionate Mind Training for Caregivers (CMT-Care Homes), looking at professional quality of life and mental health of caregivers working in RYC.The sample was composed of 127 professional caregivers from 12 Portuguese residential care homes (RCH). RCHs were randomly allocated at experimental (N = 6) and control group (N = 6). Participants were assessed at baseline, post-treatment, and 3 and 6-month follow-ups, answering to the Professional Quality of Life Scale and the Depression, Anxiety and Stress Scale. Program effects were tested using a two-factor mixed MANCOVA, with self-critical attitude and education degree as covariates.p = .014; MANCOVA showed a significant Time × Group interaction effects  on 6th August 2020. Residential youth care (RYC) is an alternative care response to youth with prior history of maltreatment, aiming to offer them a chance to have a healthy development and shape their future  were required to quickly adapt to the public health measures  and social distancing  aiming to test the effectiveness of the Compassionate Mind Training for Caregivers (CMT-Care Homes) working within RYC settings in several compassion related variables  How does the CMT-Care Homes impacts Professional Quality of life and Mental Health symptoms among caregivers working in RYC settings? (2) Are the effects of CMT-Care Homes in these variables sustained across time? Considering that the pandemic situation started during the current CRT, secondary questions are: (1) Was the CMT-Care Homes useful to deal with the pandemic situation? (2) Was the CMT-Care Homes useful to deal with children and youth within RCHs during lockdowns? In accordance with previous research testing compassion-based approaches in helping settings . The following cluster eligibility criteria were considered: (1) RCHs that receive youths aged between 12 and 25 years old, located in the center region of Portugal were included; (2) RCHs specialized in mental and behavioral disorders and/or substance abuse problems were excluded, because they adopt different and specific intervention models. Within the selected RCHs, caregivers who were directly involved in the delivery of services to youth on a regular basis were invited to collaborate.A total of 127 professional caregivers accepted to participate. Randomization took place at the cluster level, after baseline. Six RCHs were allocated to the treatment group , and six RCHs were allocated to the control group . From the six RCHs allocated to the treatment group, four RCHs were mixed and two received only females, accommodating from 15 to 45 children and youth. These RCHs had between 10 and 21 professionals with different roles. The six RCHs of the control group accommodated from 15 to 40 children and youth, four were mixed and two were gender specific, one for females, and the other one for males. These RCHs had between 14 and 23 professionals with different roles. All RCHs included in this study were 24/7 open group homes , they are located in urban and rural areas on the center of Portugal mainland, and receive mostly nationwide children and youth referred by the child protection services. In Portugal, RCHs have the main goal of time-limited protection of youth at-risk, aiming to ensure their safety, well-being, education, and healthy development. Most placements are due to maltreatment , and the remaining are due to abandonment by caregivers or the lack of family support ISS, . All RCHParticipants were mostly female (89%), and were aged between 22 and 62 years old, with a mean age of 43.99 SD = 10.96). The majority of participants were married (69%), 23% were single and 7.9% were divorced. Participants had been working within RYC settings for less than a month to 39 years , having a technical , educative  or support  function. Half of them (52%) reported they were working in shifts. Concerning educational level, 44.1% had a higher education degree, 19.7% reported having completed high school, and 36.2% some level of elementary or middle school education. No significant differences between groups were found in sociodemographic features  repeated measures (4 assessments) between factors, using G*Power, version 3.1.9.7, considering alpha = 0.05, a medium effect size (Cohen’s f = 0.36) to obtain at least 80% power, assuming a 0.80 correlation coefficient within repeated measures. Under these assumptions, a total of 54 caregivers should be enrolled, 27 in each experimental condition.The CMT-Care Homes is a manualized program developed for professional caregivers working in RYC. Main goals are to cultivate a compassionate-self and foster a caregiving mentality in RYC. It is strongly based on the Compassion Focused Therapy theoretical framework  and Compassion Mind Training practices  Gilbert,  applied All sessions present the same structure . Program contents are organized across three modules: (1) Our mind according to a compassion-based approach ; (2) Compassionate mind training ; and (3) a Final session . Contents are explored through psychoeducation and experiential practices followed by group opportunities to debate and share experiences. Considering that the transfer of learnings from training to everyday life constitutes a recurrent problem in RYC , Burnout (BO) and Secondary Traumatic Stress (STS). Participants are instructed to indicate how frequently each item was experienced in the workplace, during the previous 30 days, using a 5-point scale . The original version reported internal consistency values of 0.88 for CS, 0.75 for BO, and 0.81 for STS Stamm, . The PorDASS-21 is a 21-item self-report scale designed to assess symptoms of depression, anxiety, and stress. Participants are asked to rate how much each statement applied to them during the previous week, using a 4-point scale . In the original version, the DASS-21 subscales presented high internal consistency: Depression α = 0.91, Anxiety α = 0.84, and Stress α = 0.90 . In the original version, the scale has a total score (α = 0.92) and six subscales , with alpha values ranging from 0.75 for Mindfulness to 0.81 for Over-Identification Neff, . In the Considering that Covid-19 pandemic co-occurred with 3 and 6-month follow-up assessments, a brief questionnaire was developed to address the level of anxiety that the pandemic triggered on caregivers. It was assessed through one item question (“Please indicate the level of anxiety that the current situation of COVID-19 causes you”), ranging from 0 “nothing” to 10 “extremely”. For the treatment group, the questionnaire also addressed the level of usefulness of the CMT-Care Homes to deal with the pandemic  and with children and youth during lockdown measures , using the same scale.Written informed consent was sought at the cluster  and at the individual level , before randomization. Participants were informed of the goals and procedures, and were asked to voluntarily participate, with no incentives offered for participation. Anonymity was guaranteed, with the use of respondent-specific codes, which were also used to link the data from one timepoint to the other. Caregivers were assessed through self-report measures at baseline, post-treatment, 3 and 6-month follow-up. Considering that the Covid-19 outbreak started during the current CRT, at 3 and 6-month follow-up caregivers were also asked to answer to a questionnaire about the level of anxiety concerning pandemic and usefulness of the program in that context. Due to the pandemic situation, data were collected in person by a researcher assistant (when possible) or were sent to each RCH to be filled out individually. After the baseline assessment, a computer-generated randomization was conducted at the cluster level, following a completely randomized design by the third author of this paper. Each RCH  was randomly assigned to treatment or control group . The CMT-Care Homes program was delivered in accordance with the handbook, in a face-to-face format, weekly (2.5-h session) in each RCH, to a group of 6–12 participants, over approximately 3 months, from October 2019 to February 2020. All sessions were delivered by the first author, who is a clinical psychologist trained in cognitive-behavioral interventions and compassionate approaches.p < 0.05). Considering that deletion of cases would lead to a substantial loss of subjects, missing values of participants with less than 20% of missing data in one outcome variable were dealt via linear interpolation imputation method  assumptions  mixed MANCOVA was conducted. In accordance with former research, baseline levels of self-critical attitude were controlled due to individual differences in self-criticism on the response to compassion-based interventions . The main reasons for not completing the whole program were working in shifts/day off, vacation, brief medical discharge or urgent professional diligences. Four caregivers (6.78%) who attended less than 60% of the sessions were excluded from the analyses.All caregivers from the 12 RCHs accepted to participate and completed the baseline assessment (N = 127)  or control (N = 34) groups. At 3-month follow-up, 72.1% of the participants at CMT-Care Homes continued to practice exercises and 92.9% still applied the learnings related with the program. At 6-month follow-up percentages were 61.9% and 78.6%, respectively.Of the 61 caregivers allocated to the control group, 51 (83.61%) completed the posttreatment assessment, one left the study due to cancellation of the job contract, one was transferred to another social response, and eight dropped out the study. Nine participants were lost to assessment at 3-month follow-up (14.75%): four of them due to contract cancelation, four due to medical discharge, and one dropped out. At 6-month follow-up four participants were lost to assessment (6.56%): one due to medical discharge, one was transferred to another social response, and two dropped out. Four participants (6.56%) were excluded from analyses due to missing data. In total, 77 caregivers , aged between 22 and 62 years old, were included in the analysis, at the experimental (p > 0.05)  corresponding to a small effect size , results showed that caregivers from the treatment group gradually reduced their burnout levels from preintervention to 6-month follow-up (Cohen's d = 0.30). In turn, for the control group, burnout levels were kept stable from preintervention to 6-month follow-up (Cohen's d = 0.13).In what concerns depression, caregivers from the treatment group progressively improved from preintervention to 6-month follow-up (Cohen's d = 0.49), while the control group did not change across time (Cohen's d = 0.10). Regarding anxiety symptoms, the treatment group gradually decreased anxiety levels from preintervention to 6-month follow-up (Cohen's d = 0.60). In turn, the control group showed a tendency for increasing anxiety from preintervention to 6-month follow-up (Cohen's d = 0.35). These differences corresponded to small to moderate effect sizes.Anxiety related with the Covid-19 outbreak was correlated with outcome variables measured at follow-up assessments, showing significant positive, but weak, associations . Exceptions were for stress and compassion satisfaction. At 3-month follow-up, corresponding to the onset of the pandemic and lockdowns, stress and anxiety related to the pandemic achieved a significant and moderate positive correlation (r = 0.406), but this association was not significant anymore at 6-month follow-up, when lockdown measures were relaxed. Compassion satisfaction and anxiety related with the pandemic did not correlate at 3-month follow-up, but showed a significant and weak negative correlation at 6-month follow-up (r = -0.293).t (73) = -2.295; p = 0.025; treatment group M = 5.74, SD = 2.72 and control group M = 7.06, SD = 2.14), with controls showing higher levels. Groups did not significantly differ at 6-month follow-up (t (72) = -1.366; p = 0.176; treatment group M = 5.93, SD = 2.47 and control group M = 6.67, SD = 2.10).Groups significantly differed at the level of anxiety associated with the pandemic at 3-month follow-up  and with children and youth during lockdowns .Although CMT-Care Homes was not designed to deal with a pandemic, caregivers recognized the program usefulness when dealing with the contingencies associated with the Covid-19 outbreak  was carried out in order to test for intervention effects on professional quality of life and mental health outcomes. When controlling for education degree and self-critical attitude at baseline, MANCOVA revealed statistically significant Time x Group interaction effects of the CMT-Care Homes on burnout, depression, and anxiety, with small to medium effect sizes. Improvements in the treatment group were observed at follow-ups. These findings are in line with previous research, highlighting the beneficial effect of compassionate-based interventions on psychological distress and mental health symptoms  have been used to assess psychophysiological correlates of compassion, emotion regulation, and stress (Schmid et al., To conclude, findings highlight the utility and relevance of compassion-focused interventions in RYC settings, showing the potential benefits of the CMT-Care Homes in helping caregivers to develop socio-emotional competencies for caring for their own mental health and professional quality of life, while taking care of vulnerable youth.


Mycobacterium tuberculosis (Mtb). The convergence of nucleosides and terpene pathways in the Mtb complex appears to have emerged late in its evolutionary history. 1-TbAd (PDB ID: 3WQK) is a prominent chemical marker for Mtb and may contribute to its virulence-related properties when exported extracellularly. We gathered a comprehensive set of 270 phytochemicals from diverse Ayurvedic texts and treatment traditions. Subsequently, we conducted structure-based molecular docking analyses to identify compounds exhibiting the strongest binding affinity for 1-TbAd, highlighting their potential as drug candidates. These selected compounds were further subjected to an in-vitro growth inhibition assay against the reference strain Mycobacterium tuberculosis h37rv. Among the candidates, Asiaticoside A (ASA) emerged as a promising candidate from the pool of 270 compounds. To assess the impact of ASA on 1-TbAd expression, we employed a PCR-based mRNA expression assay, revealing ASA's ability to downregulate 1-TbAd expression in extensively drug-resistant MTb strains. Remarkably, the conventional drug rifampin showed no such effectiveness in our experiments. We further conducted molecular dynamic simulations to explore the interaction between ASA and 1-TbAd in a cellular-like environment, confirming the stability of their interaction. Also, we predicted ASA's stability toward causing inducing the random mutations in the target gene. With this, we propose a novel target and its modulator to treat extensively drug-resistant MTB.In nature, terpene nucleosides are relatively rare, with 1-tuberculosinyladenosine (1-TbAd) being an exclusive feature of The online version contains supplementary material available at 10.1186/s13568-023-01616-w. In-silico screening studies for identifying the hit compoundmRNA expression analysis for validation of hit compoundRandom in-silico mutagenesis and Molecular dynamic simulation studies for evaluating the efficiency of Asiaticoside A.The online version contains supplementary material available at 10.1186/s13568-023-01616-w. Despite various nationwide tuberculosis (TB) eradication programs in the twenty-first century, tuberculosis is still a leading cause of mortality and morbidity worldwide. Tuberculosis (TB) is one of the top 13 causes of death worldwide and the most common infectious disease , drug resistance can be explained by two main factors and their interactions: extrinsic factors related to the social determinants of TB in populations and the quality of TB control and prevention services and intrinsic factors resulting from the acquisition of mutations in drug-resistant genes  was identified as a potential growth inhibitor for XDR Mtb. Asiaticoside A is commonly found in Mycobacterium tuberculosis h37rv was obtained from the district Tuberculosis laboratory . It has a rpoB gene mutation (gene accession number: JN037845) and has resisted the first, second, and third lines of TB drugs in primary screening. In addition, we also obtained a sample for drug-sensitive tuberculosis from the same laboratory. The culture was then inoculated into the Middlebrook medium (Himedia) supplied with 0.05% Tween 80 and albumin-dextrose-catalase. The culture was maintained by transferring in the fresh medium every 30 days. Madasiatic acid, Asiaticoside A(ASA), β-sitosterol, Cystargamide B, Myristic acid, Palmitic acid, Kalmeghin, Oleanolic acid, Longicyclene, Oleanane, and Amyrin were purchased from Sigma-Aldrich.Mtb H37Rv was initially isolated from a patient with pulmonary tuberculosis in 1905 by Albert Calmette and Camille Guérin at the Pasteur Institute in Paris, France. The strain was maintained and distributed by American Type Culture Collection (ATCC 27294) centre. For our study, a clinical sample from extensively drug-resistant Mycobacterium tuberculosis (Mtb) establishes human infection through various mechanisms, mainly involving the three sets of gene products. First, we grouped the genes based on a cellular role, such as multiplication, cell-wall biosynthesis, and mycolic lipid synthesis. After that, we manually investigated each gene product for its experimentally validated ligand. Then, we identified the fifteen unmapped targets . First, the protein structures were obtained from the protein data bank (PDB)  and Ayurvedic pharmacopoeia. The queried keywords were tuberculosis (kshay rog) and antibacterial activity. We identified 270 phytochemicals, and their chemical structures were obtained from PubChem  of activated XDR Mtb culture in 100 µl of cultivation media. Initially, the gradient of ASA, 1-5 µg of concentration, was created in a microtiter plate. Each set was performed in triplicates, and the ASA-free well was considered a negative control. The covered microtiter plate was incubated at 37 ºC for 24 h. The absorbance was recorded at 600 nm in the plate reader . The Kanamycin (MIC: 0.78 µg/ml) and Rifampin (MIC: 1 mg/ml) were tested in separate wells as a positive control for the study.The in-vitro antimicrobial assays using the well-diffusion method were performed for each (stock 1 mg/ml) of the ten phytochemicals; only the ASA gave a notable zone of inhibition at the studied concentration and hence opted for further optimization. The MIC of ASA was determined by inoculating the 50 µl (2×106 cells/ml). After a 24-h incubation period, total RNA was extracted from the treated cultures using TRIzol reagent , and the purity of the RNA template was assessed using a NanoDrop ND-1000 spectrophotometer . Subsequently, we designed gene-specific primers for our target gene  Mtb (2*10The GROMACS package program (version 2022.2) was used to simulate the stability of a docked complex in a natural cell environment , the binding free energies for all complexes were calculated. Total G binding was calculated by examining each protein–ligand complex's free solvation energy (polar and nonpolar solvation energies) and potential energy  . Of 10 such compounds, ASA gave higher binding affinity towards the multiple Mtb-specific targets: 1MOP, 3WQK, and 6OR2. The gene product of 1MOP catalyzes the condensation of pantoate with beta-alanine, which is essential for synthesizing vitamin B5. Ciulli et al. (2015) reported it as a potential antimicrobial target. The target protein 6OR2 synthesizes the Mtb membrane  on extensively drug-resistant tubercle bacilli and 100% on reference strain E. coli. Here, we further screened ASA for gene expression analysis.Next, we performed the growth inhibition assay on XDR Mtb. ASA gave almost 90% growth inhibition, while no other phytochemicals gave a significant bacteriostatic effect. The earlier reports have established ASA as a neuroprotective agent that can cross the blood–brain barrier . An apparent assumption indicates the ASA-mediated down-regulation of the 1-TbAd could be one of the mechanisms for the ASA-induced growth inhibition.The RT-qPCR assay was used to investigate the relative fold change in the expression of 1-TbAd post-ASA treatment. The fold change was computed using C) and reference standard  can be seen in Fig. The best-docked complex of the molecular docking study was simulated to predict the in-vivo stability of the ligand and target. The complex of the ASA-3WQK had a binding score of -11.8 kcal/mol, and the direct contact of multiple amino acid residues was observed. If the simulation has stabilized, RMSD analysis can show that the changes at the end of the simulation are centred on a thermally and energetically stable conformation. From the obtained trajectory analysis, the RMSD of protein Carbon atom (Ca), backbone, and heavy atoms were observed in the range of 0.1–0.3 nm and 0.1–0.7 nm, respectively. The adjacent Cα atoms fluctuated in the range of 10 to 25 ns and finally equilibrated after 30 ns of simulation with an average RMSD value of 0.3 nm. However, as the protein's size increases, this value range widens. ASA's average LigFitLig RMSD is less, indicating that the molecules did not undergo significant rotation. A lock-and-key type of phenomenon involving ligand binding in the protein cavity, Ligfit Prot values are easier to interpret. The LigFit Prot graph of our hit  is not required for its thermodynamic stability (binding affinity) Du et al . Here, tThe radius of gyration (Rg) allows us to assess the changes in compactness of a ligand–protein complex. Finally, higher Rg reduces the compactness of the ligand–protein complex. During the MD simulation, Rg is used to determine if the complexes are stable, folded or unfolded. 3WQK-ASA has an average Rg value of around 2.05 nm . For ligand–protein complexes, SASA was calculated to determine the extent of conformational changes that occurred during the interaction. The SASA value vs. time plot for each protein–ligand combination is shown in Additional file The calculation of binding free energy change provides information about the ligand's ability to interact strongly with the amino acids of the protein. The energy released (∆G binding energy) as a result of bond formation, or rather ligand–protein interaction, is in the form of binding energy and determines the stability of any given protein–ligand complex. A favorable reaction has a negative free energy. Table It is discovered that ASA have a negative ∆GBinding energy. The lead molecule ASA had an MM-GBSA score of -90.07, whereas the reference molecule had a significantly lower MM-GBSA score of -80.82. Based on these findings, it is possible to conclude that ASA had a higher free binding energy score than the reference compound. The compound has similar energies corresponding to van der Waals interactions, indicating that it prefers to be near the interacting amino amides of 3WQK. The compound has negative Coulomb energy values, which describe potential energy in systems.(Table S7). Next, we identified the common residues that likely play a role in direct association with ASA and Rifampin. For ASA-1-TbAd that are Gly35, Thr36, and Tyr90, we replaced them with the residues of the same group (polar to polar), e.g. Glycin35 with the Cysteine gave double change in Gibbs free energy (ΔΔG) at 0.817 kcal/mol representing the stable interactions shown in Additional file −1K−1. It showed that Thr to Trp change in 1-TbAd resulted in rigid structure and reduced molecular flexibility (Additional file Though many drug candidates have been tested for MTb and showed considerably good antibacterial activities, in most of the drugs, drug-resistance phenomena were noted later (Maddila et al Additionally, the ligand-binding affinities to mutated versions were evaluated by docking studies. The result shows some non-significant increase in binding affinity in a few sets for the scrutinized association. However, overall, the ligand-target interaction is robust and stable towards the residue changes for ASA.Butler et al.  tested pCentella Asiatica is a traditional medicinal plant famous in Asian folklore. ASA was extracted from the plant and speculated to promote wound healing (Lee et al interaction is fairly stable with many other point mutations. With this, the in-silico and in-vitro assays have recognized the ASA as a putative lead compound for the 1-TbAd. The target's robustness can be evaluated in the future by performing a site-directed mutagenesis study. The research presents an alternate opportunity for combating the drug-resistant XDR Mtb, otherwise untreated.In conclusion, we first reviewed Mtb gene targets and their possible modulators Table . Then, wAdditional file 1: Table S1. Commercial drugs; targets and their mode of action. Table S2. Active chemical constituents and their associated identifier of the traditional herbs. Table S3. Mapped gene targets with a significant role in MTB aetiology. Table S4. Primers for 1TbAd. Table S5. Mutation in the familiar residue of the 1-TbAD. Table S6. Mutation in the familiar residue of the rpoB. Table S7. Prediction of the active binding pockets for 1-TbAd-3WQK. 14. Figure S1. A plot SASA Value A 3WQK_ASA B rpoB_Rifampin. Figure S2.a Wild type b Color codes are displayed on the right panel, and mutant residue is colored in the light-green and depicted in the stick. c The vibrational entropy change that occurs during mutation causes amino acids to change color. The rigidification of the structure is represented by the color blue.


Water absorption capacity was reduced by the incorporation of AgNPs, except for the chitosan-reduced composite, which showed an enhanced water absorption capacity of 344%. All BC-Ag composites displayed very strong antibacterial activities against Staphylococcus aureus and Escherichia coli. These results also highlight the potential uses of BC-Ag composites for various applications.Composite films of bacterial cellulose-silver nanoparticles (BC-Ag) were prepared by different methods of in situ reduction of silver ions, using sodium hydroxide, ascorbic acid, chitosan, and UV irradiation. The effects of the reduction methods on their properties were investigated. The chitosan-reduced composite exhibited dispersed silver nanoparticles (AgNPs) within the nanocellulose matrix with the smallest size, while the ascorbic-reduced composite displayed the largest size. The incorporation of AgNPs tended to reduce the crystallinity of the composites, except for the ascorbic-reduced composite, which exhibited an increase in crystallinity. Mechanical testing revealed that the ascorbic-reduced composite had the highest Young’s modulus of 8960 MPa, whereas the UV-reduced composite had the highest tensile strength and elongation at break. Thermal analysis of BC-Ag composites indicated similar glass transition temperature and decomposition profiles to BC, with additional weight-loss steps at high temperatures. The sodium hydroxide-reduced composite demonstrated the highest electrical conductivity of 1.1 × 10 Gluconacetobacter xylinus. Bacterial cellulose (BC), produced by bacteria, differs from plant cellulose as it lacks hemicellulose, lignin, and other compounds present in plant cellulose [Cellulose is one of the most abundant, readily available, and inexpensive common polymers on earth with an annual production of around 75 billion tons . Celluloellulose , which eellulose . These uDue to superior properties compared to plant cellulose, BC has found its use in various applications, such as tissue engineering, electronic devices, biomedical applications, and drug delivery systems. In the biomedical field, BC serves as a wound-dressing material, artificial skin, vascular grafts, scaffold for tissue engineering, artificial blood vessel, and medical pads ,9. BC ha2O), has been widely used for antibacterial applications. The unique physicochemical properties of nanosilver, including its high surface-to-volume ratio and inherent biocidal activity, make it a promising candidate for combating bacterial infections [+ to Ag0 [Silver, in the form of nanoparticles (AgNPs) and oxides (mainly Agfections . Howeverfections . BC cont+ to Ag0  and offe+ to Ag0 . As a re6H8O6), and chitosan solutions, and photochemical reduction using UV irradiation. The BC and BC-Ag composites were characterized using various techniques, including X-ray diffraction (XRD), a field-emission scanning electron microscope (FE-SEM), Fourier transform infrared spectra (FT-IR), a universal testing machine (UTM), and electrochemical impedance spectroscopy (EIS), as well as thermal analysis techniques, which include thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, the antibacterial activities of BC-Ag composites were evaluated using the colony-forming count method against gram-positive bacteria (S. aureus) and gram-negative bacteria (E. coli).This research aims to investigate the influences of different methods of in situ reduction of silver ions in a bacterial nanocellulose matrix on the properties of BC-Ag composite films using facile, inexpensive, and easily replicable approaches. The methods applied in this study include chemical reduction using sodium hydroxide (NaOH), ascorbic acid   was purchased from RCI Labscan Ltd. . Sucrose and ammonium sulfate were purchased from Ajax Finechem Pty Ltd. . Acetic acid was purchased from Mallinckrodt Chemicals . Sodium hydroxide (NaOH) pellets were purchased from Kemaus . Chitosan from shrimp shells with low molecular weight (∼25 kDa) was purchased from Marine Bio Resources Co., Ltd. . Ascorbic acid (C6H8O6) was purchased from Loba Chemie Pvt Ltd. .The stock culture of v/v) acetic acid solution , 5.0% (w/v) sucrose, and 0.5% (w/v) ammonium sulfate). The mixture was then sterilized at 110 °C for 5 min. Pre-cultures were prepared by transferring 15 mL of the G. xylinus stock culture to a 500 mL Erlenmeyer flask containing 300 mL of medium. These pre-cultures were statically incubated at 30 °C for 7 days. Subsequently, 5.0% (v/v) of the incubated medium was added to 75 mL of the activated medium, which was then placed in a glass Petri dish with a diameter of 14.5 cm and incubated at 30 °C for 7 days.BC was produced through a biosynthesis method utilizing coconut water as the primary ingredient. The culture medium was prepared by combining coconut water with a 1.0% (w/v) NaOH solution at room temperature for 24 h to eliminate any attached media and bacterial cells. Following that, BC was rinsed with running water for 30 min and further washed with deionized water (DI) until the pH became neutral. Afterward, the purified BC pellicle was stored in DI water at 4 °C for subsequent usage.BC synthesized by the bacteria was harvested at the air-liquid interface of the culture broth after 7 days. Then the harvested materials were purified by rinsing them with deionized water (DI) for 30 min, and then they were immediately placed in 1.0%  for 5 h [BC-Ag composite films were prepared using different methods, some of which were modified from the previous reports. For the reduction by NaOH, ascorbic, and UV irradiation, BC pellicles were pretreated by immersing them in 0.02 M AgNO for 5 h ,23. 3 solution were rinsed with DI water to eliminate excess AgNO3 solution. Subsequently, the pellicles of BC-Ag ions were reduced by immersing them in a solution containing 0.12 M ascorbic acid or 0.12 M NaOH for 30 min [3, 2.0% (w/v) chitosan, and 1.0% (v/v) acetic acid, stirring for 2 h, and leaving them in the dark for 2 days. Afterward, the mixture was incubated at 75 ± 2 °C for 5 h. The chemical reduction was conducted using NaOH ascorbic acid, or chitosan. For the reduction of Ag ions using NaOH and ascorbic, the pretreated BC pellicles that had earlier been immersed in the 0.02 M AgNOr 30 min ,24. For After the reduction processes, the pellicles of BC-Ag nanoparticles were then washed with DI water for 10 min to eliminate excess chemicals and then were air-dried at room temperature (30 °C) and stored in plastic film at room temperature. The composite films of BC-Ag nanoparticles prepared by reducing silver ions using UV irradiation, NaOH, ascorbic acid, and chitosan were denoted as BC-Ag(UV), BC-Ag(NaOH), BC-Ag(Ascorbic), and BC-Ag(Chitosan), respectively.−1 with a resolution of 4 cm−1.The functional groups and chemical structure of the BC and BC-Ag composites were determined by Fourier transform infrared (FT-IR) spectroscopy  in the ranges of 4000–400 cmThe morphologies of the BC and BC composites were observed by scanning with an electron microscope and energy dispersive X-ray spectrometer using a Field Emission Scanning Electron Microscopy . The specimens were sputtered with gold. The SEM–EDS was performed at an accelerating voltage of 5–15 kV.2). To ensure repeatability, a minimum of five specimens for each sample type was tested. The test was performed at a temperature of 25 °C.The mechanical properties of dry films of BC and BC-Ag composites, including Young’s modulus, tensile strength, and elongation at break, were assessed following the ASTM D882 (2004) standard using a Universal Testing Machine . The samples were prepared in the form of rectangular film sheets (1 × 5 cmd) and residual weight were analyzed using a thermogravimetric analyzer . Film samples weighing between 3–6 mg were subjected to heating from 30 to 600 °C under a nitrogen atmosphere, with a constant heating rate of 10 °C/min.The decomposition temperature (Tg) was determined using a differential scanning calorimeter . A total of 7–10 mg of the sample was loaded into an aluminum pan. The heating process took place under a nitrogen atmosphere, ranging from −100 to 300 °C, with a constant heating rate of 10 °C/min.The glass transition temperature  using Cu radiation. The measurements were conducted in the scan range of 2θ from 10–80° with an accelerating voltage of 40 kV and electric current of 40 mA. The crystallinity index (CI) was calculated using DIFFRAC.EVA software (Version 6.0.0.7) with the following formula:The electrical properties of BC and BC-Ag composites were determined by Electrochemical Impedance Spectroscopy  at 25 °C, and Nyquist plots were obtained using the frequency range from 200 kHz to 1 Hz.2) in DI water at room temperature until they reached equilibrium. The initial weights of the dry samples were recorded as Wd. After removing the samples from the water and eliminating any excess water on the surface using Kimwipes paper, the weight of each water-swollen sample was then measured, and the weights of the hydrated samples were recorded as Wh. This process was repeated until no further weight change was observed. The WAC was calculated using the following formula.The water absorption capacity (WAC) was evaluated by immersing the weighed and dried samples  were sterilized with UV light for 2 h, and then 1 mL of the bacterial cell suspension, with an initial cell density of 1.5–4 × 106 CFU/mL, was applied to each sample. Following a 24 h incubation period at 37 °C, the samples were subjected to thorough shaking at 200 rpm for 1 min in the presence of 10 mL of pH 7.4 phosphate-buffered saline (PBS). Subsequently, the PBS solution containing the cells was cultured on agar plates and incubated at 37 °C for another 24 h. Finally, the resulting cell colonies were counted.The modified JIS Z 2801 method was used to evaluate the antimicrobial properties of composite films against 2 BC hydrogel was 11.02 g (the weight of 5 × 5 cm2 dry BC was 0.0964 g). The thickness of the BC hydrogel was approximately 5 mm. To prepare the composites of BC-Ag ions, purified BC pellicles were immersed in AgNO3 solution for two days in the dark for the complete adsorption of Ag+ into the BC matrix. Abundant hydroxyl groups in the BC provide anchoring sites and react with Ag+ [BC is produced from the biosynthesis process using inexpensive coconut water waste as an alternative substrate, which contains nutrient and minerals for microbial growth , insteadwith Ag+ . BC coulwith Ag+ , prevent3 solution, the BC film appeared slightly darker, while the AgNO3 solution remained clear. However, under the reduction with chitosan, the BC pellicles that were immersed in AgNO3-chitosan solution became brown and the solution color turned from clear yellow to dark brown. During the incubation at 75 ± 2 °C for 5 h, the colors of the AgNO3-chitosan solution and the composite film were gradually darkening over time. In this case, chitosan, which contains an amide group, is able to form an intermolecular bonding with the hydroxyl groups of BC [3-treated BC film immediately underwent a color change when immersed in the solution of reducing agents. The color of the composite film turned silvery-brown when immersed in the ascorbic acid solution and turned dark brown when immersed in the NaOH solution. Under the reduction using UV light, the composite film gradually turned dark brown when exposed to UV light irradiation. These color changes in the solution and the BC pellicles, consistent with previous cases [After 2 days’ immersion in the AgNOps of BC  and actsus cases ,24, indi+, causing the reduction to Ag0 and the formation of dehydroascorbic acid [+ to Ag0 at room temperature under a strong alkaline condition. However, Ag+ ions were unstable under alkaline conditions, resulting in the rapid formation of insoluble Ag2O particles, which could be reduced by the hydroxyl group of the cellulose, creating another pathway for forming silver nanoparticles. In the UV irradiation method, Ag+ ions bonded to BC fibers undergo a transformation into silver nanoparticles after being exposed to UV light for a certain period of time, which also results in the formation of Ag2O [+ ions. The reduction ability of chitosan is attributed to the strong coordination abilities and complexation interactions of NH2 groups with metal ions [The reduction mechanisms for each method are as follows. In the reduction by ascorbic acid, ascorbic acid serves as a reducing agent by providing electrons to Agbic acid . The redbic acid , who exp of Ag2O . In the tal ions . Additiotal ions .2O in BC-Ag(Ascorbic). Ag2O has a black or dark brown color, while Ag nanoparticles exhibit various colors depending on their size and shape. All BC-Ag films showed a substantial decrease in opacity compared to transparent BC films, ultimately leading to the complete obstruction of light. The thickness of BC, BC-Ag(NaOH), BC-Ag(Ascorbic), BC-Ag(UV), and BC-Ag(Chitosan) films were measured to be 32 ± 3, 51 ± 4, 34 ± 2, 31 ± 3 and 90 ± 10 µm, respectively. Notably, the BC-Ag(Chitosan) films exhibited a significant increase in thickness, which could be attributed to the diffusion of chitosan into the BC, which formed the intermolecular hydrogen bonds in the BC network [2O, in the nanocellulose matrix.The transparent and colorless BC films are darkened by the incorporation of Ag, as depicted in  network ,32, resuFE-SEM analysis was performed on dried BC and BC-Ag composite films, with the observed surface morphology at 50,000× magnification presented in Silver nanoparticles with varying diameters can also be seen as white dots on the surface of BC-Ag films. The BC-Ag(Ascorbic) film exhibits the largest diameter of AgNPs, while the BC-Ag(Chitosan) film exhibits the smallest diameter. The smaller size of AgNPs in BC-Ag(Chitosan) can be attributed to the stabilizing or capping capabilities of chitosan on metal nanoparticles , which pEDX scanning is also utilized to determine the chemical composition and distribution of Ag on the surface of the BC-Ag composites. −1, indicating the stretching vibration of the abundant O-H groups within the BC network [−1, which might be caused by AgNPs interfering with the hydrogen bonding of the BC network. The subsequent peaks observed at approximately 2921 cm−1 and 2852 cm−1 can be attributed to the asymmetric and symmetric stretching vibration, respectively, of the C-H groups in the cellulose structure [−1, which could be assigned to non-conjugated C-C stretching [−1 is attributed to the stretching vibration of the C-O and C-C groups [−1 is assigned to the H-O-H bending of the absorbed water molecules [−1 is due to OH in-plane bending [FTIR analysis was performed to investigate the spectra shift and chemical structure. The FTIR spectra of BC and BC-Ag composites are presented in  network . The peatructure . These pretching . The preretching . The intC groups . Further bending . 2O and (100) plane of hexagonal Ag2O (JCPDS No.72-2108) [2O peaks are absent in BC-Ag(Ascorbic).The XRD patterns of BC and BC-Ag composites are shown in 72-2108) . Notably0 and BC, as well as the absence of Ag2O, which is present in other BC-Ag composites.The crystallinity index (CI) was calculated using DIFFRAC.EVA software. The calculated crystallinity index values for BC, BC-Ag(NaOH), BC-Ag(Ascorbic), BC-Ag(UV), and BC-Ag(Chitosan) composites are 78.5%, 68.3%, 83.3%, 69.6%, and 48.6%, respectively. Among the BC-Ag composites, the highest degree of crystallinity was observed in BC-Ag(Ascorbic), while BC-Ag(Chitosan) showed the lowest degree of crystallinity. Except for BC-Ag(Ascorbic), the incorporation of AgNPs resulted in a slight reduction in the crystallinity of the composites, which could be due to silver interfering with hydrogen bonds within the BC matrix , while cThe mechanical properties of BC and BC-Ag composites were investigated using a Universal Testing Machine to determine Young’s modulus, tensile strength, and elongation at break. The results of the testing are presented in 2O, other BC-Ag composites showed lower crystallinity, which might affect the mechanical properties of the films. The increase in Young’s modulus of BC-Ag(Ascorbic) could be partly attributed to the enhanced crystallinity, which has been known to increase Young’s modulus in polymers [The mechanical properties of BC-Ag composites varied greatly by the method of reduction. For BC-Ag(NaOH) and BC-Ag(UV) composites, Young’s modulus of the composites dropped dramatically by approximately 50%. Similarly, BC-Ag(Chitosan) exhibited a significant decrease in Young’s modulus by about 23%. On the other hand, the composites of BC-Ag(Ascorbic) demonstrated a remarkable increase in Young’s modulus, reaching 8960 MPa, which was almost twice the value of the pristine BC. These findings are consistent with the crystallinity values obtained from XRD analysis. Except for BC-Ag(Ascorbic), which did not contain Agpolymers . Howeverpolymers . The comBC-Ag(NaOH) and BC-Ag(UV) composites demonstrated a moderate increase in both tensile strength and elongation at break as compared to BC. Alternatively, BC-Ag(Ascorbic) showed a significant increase in Young’s modulus, but elongation at break of the film was decreased by about 60%, while the tensile modulus remained relatively unchanged. The significant decrease in elongation at break for BC-Ag(Ascorbic) could be attributed to the higher rigidity and stiffness of the materials, which resulted from the inclusion of highly crystalline silver nanoparticles. In the case of BC-Ag(Chitosan), the presence of chitosan inside the matrix could cause a reduction in flexibility, making the composites noticeably more brittle and resulting in a substantial decrease of approximately 80% in both tensile strength and elongation at the break as compared to BC. 2O and the capping layers of AgNPs. Additionally, BC-Ag(Chitosan) composite exhibited an additional weight loss at around 240 °C, likely due to chitosan decomposition [The thermal properties of BC and BC-Ag composites were investigated using differential scanning calorimetry (DSC) a and theposition . The resg) was determined using DSC thermograms; the obtained Tg data are tabulated in 2O and the capping layers of AgNPs, as well as the decomposition of chitosan in the case of BC-Ag(Chitosan). The Tg values obtained from DSC were relatively similar across all samples, with BC-Ag composites having slightly lower or similar Tg values than BC, except for BC-Ag(Ascorbic), which was 4.8 °C higher than pristine BC. This result is in accordance with crystallinity index (CI) values obtained from XRD analysis, where BC-Ag composites typically exhibit lower CI, except for BC-Ag(Ascorbic).The glass transition temperature  exhibited the highest conductivity, which was approximately three orders of magnitude higher than pristine BC. The highest conductivity from BC-Ag(NaOH) could be attributed to the high silver content within the matrix. This is supported by the highest residue observed at 600 °C in the TGA analysis  study was carried out in a frequency range from 200 kHz to 1 Hz to measure the electrical properties of BC and BC-Ag composites. analysis , while tThe water absorption capacity (WAC) values of BC and BC-Ag composites were determined using dried films, and the results are illustrated in Apart from BC-Ag(Chitosan), the other BC-Ag composites showed a lower WAC, which could be attributable to the incorporation of AgNPs into the BC matrix, which made the BC structure denser with lower porosity, thereby reducing water penetration and the WAC of the films. In contrast, the increase in the WAC values for BC-Ag(Chitosan) could be attributed to the highly hydrophilic nature of chitosan, which exhibited simultaneous interaction with both water molecules and BC chains , resultiS. aureus and E. coli, which served as models of Gram-positive bacteria and Gram-negative bacteria, respectively. The test results are presented in S. aureus and E. coli, respectively. In contrast, the growth of S. aureus and E. coli was strongly inhibited by all types of BC-Ag composites (reduction from ~3 × 106 CFU/mL to 0 CFU/mL), to the extent that no visible colonies were observed or detected on the agar plates  upon contact with moisture [BC and BC-Ag composites were tested for antibacterial activities against r plates . These rmoisture , which imoisture . S. aureus and E. coli.Different reduction methods for synthesizing BC-Ag composites exhibit distinct advantages and disadvantages, as summarized in g of the composites were quite similar to those of BC; only a small increase in Tg was noticed for BC-Ag(Ascorbic). Additional weight-loss steps were observed for BC-Ag composites at high temperatures during TGA analysis. Electrochemical impedance spectroscopy analysis demonstrated that BC-Ag(NaOH) exhibited the highest conductivity at 1.1 × 10−7 S/cm, which was approximately three orders of magnitude higher than for pristine BC, while the conductivity of the other BC-Ag composites, except for BC-Ag(Chitosan), increased to some extent. The WACs of BC-Ag composites tended to decrease by the incorporation of AgNPs; however, the WAC of BC-Ag(Chitosan) increased owing to the presence of chitosan within the BC matrix. Antibacterial tests showed that all BC-Ag composites possessed a very strong inhibitory effect against E. coli and S. aureus. These multifaceted properties of BC-Ag composites highlight their potential applications in various fields such as antimicrobial packaging, wound dressings, and biomedical devices. These findings should contribute to a better understanding of the BC-Ag composites and open avenues for further exploration and optimization of their properties for specific applications.In this study, BC-Ag composites were successfully synthesized using various in situ reduction methods to convert Ag ions to AgNPs by using sodium hydroxide, ascorbic acid, chitosan, and UV irradiation. The effect of the reduction methods on various properties was investigated. It was observed that AgNPs were effectively attached to BC fibers. BC-Ag(Ascorbic) exhibited the largest size of AgNPs dispersed in the BC matrix, whereas those prepared by using chitosan displayed AgNPs of the smallest size. The result from X-ray diffraction analysis revealed that the incorporation of AgNPs reduced the crystallinity of the composite films, except for the BC-Ag(Ascorbic), which exhibited an increase in crystallinity. The mechanical properties of the BC-Ag composites varied greatly depending on the reduction methods. BC-Ag(Ascorbic) showed a remarkable increase in Young’s modulus. The composites of BC-Ag(NaOH) and BC-Ag(UV) showed a significant increase in tensile strength and elongation at break, whereas the BC-Ag(Chitosan) composite became brittle and exhibited a significant decrease in tensile strength and elongation at break. Thermal analysis indicated that the decomposition profiles and T